Heterogeneous silicon crystal growth on a single-crystal silicon wafer

Abstract

Using a new process, a large grain polycrystalline silicon layer was grown directly from molten Si on a single-crystal silicon wafer at a rate 100 times faster than the conventional chemical vapor deposition process. A polycrystalline silicon layer was also produced on a single-crystal silicon wafer, which had an oxide layer and etched V grooves, through use of an additional ultrasonic wave effect in this process. A layer thickness of 100–600 μm and a grain size of 10 μm–3 mm were controllably obtained. After the growth of the polycrystalline layer, dislocation densities of 4×105 cm−2 for the single-crystal silicon substrate, and 2×106 cm−2 for the polycrystalline layer were obtained. Some devices were fabricated from the products of this new process, and the characteristics of these devices were investigated.